Solve for $x$ : $2\sqrt{x} - 8 = 8\sqrt{x} + 9$
Subtract $2\sqrt{x}$ from both sides: $(2\sqrt{x} - 8) - 2\sqrt{x} = (8\sqrt{x} + 9) - 2\sqrt{x}$ $-8 = 6\sqrt{x} + 9$ Subtract $9$ from both sides: $-8 - 9 = (6\sqrt{x} + 9) - 9$ $-17 = 6\sqrt{x}$ Divide both sides by $6$ $\frac{-17}{6} = \frac{6\sqrt{x}}{6}$ Simplify. $-\dfrac{17}{6} = \sqrt{x}$ The principal root of a number cannot be negative. So, there is no solution.